In the synthesis of certain substances and for other purposes it becomes necessary to control the flow of gas or liquid which may be corrosive or very reactive chemically. Heretofore, both gas and liquid valving for such process chemicals has presented very difficult problems. Valves have been proposed which attempt to isolate the operating mechanism from the process chemicals by means of flexible diaphragms or by stuffing box type glands. The latter type always have some tendency to leak and the high friction associated with them leads to problems in obtaining reliable operation. The diaphragm type seals are subject to accidental piercing and are subject to a measurably high rate of permeation by both organic solvents and acid vapors which rather quickly lead to undependable operation of the valve actuating mechanism. Bellows types of seals composed of flexible materials have also presented the problems of diaphragm type seals.
It is accordingly an object of the invention to overcome problems which have heretofore existed, to provide reliable valving of process chemicals and to provide durable valves for corrosive and chemically reactive substances which may be operated easily, manually or automatically.
Other and further objects, features and advantages of the invention will become apparent as the description proceeds.